For me, the major differences between the two are control, capability of dedicated circuits, and ease of upradeability.
Control - A good example of this is an outboard amp. A decent amp will provide better control to your speakers as far as bass, mids, and highs. I doubt it if there is a receiver that can match the "control" in speakers of 5 outboard amps(5 each and separate power supplies, transformers, memory, not to mention total power)in a 5 channel set up.
Dedicated circuit - A DAC is a good example here. A separate dac (MSB or Monarchy which are not expensive at all) performs better than any DACs on three receivers (Yamaha RXV-1, HK AVR 8000, and Onkyo TXDS777)that I had the unfortunate experienced of owning/auditioning. I kept the RXV-1 as a processor and bought a separate dac and amps for 2ch-5ch listening on my HT system. Of course, the manufacturers of these receivers have the capability to improve the DACs but the biggest limitation is the real state it will take for the circuit design inside the receiver. Remember, inside the receivers not counting the DAC, you still have to accomodate processor circuits, display and control circuits, several channels of pre-amplification and power amplication, power supplies, wirings etc. In short, outboard DACs are way better because that's all they do and there is no compromise. All the design and improvements are aimed at one purpose only, that is to improve its Digital to Analog conversion capability
Upgradeability - This is self explanatory. For separates, you can hand pick (or ear pick) the preamp/processor, amp, dacs, and cabling to your liking (or to your wife's liking). On a receiver, what you see is what you get (WYSIWYG)! Although, you can always improve amplification by buying a separate amp and using your receiver's pre-out capability. But would that mean you are "quasi-separates" already?
Of course, the descriptions above were my experienced when I was in the "receiver" state of mind. I will never go back to it IMHO since moving to separates is nothing short of a revelation to me.
...to inform, not to convince....
Control - A good example of this is an outboard amp. A decent amp will provide better control to your speakers as far as bass, mids, and highs. I doubt it if there is a receiver that can match the "control" in speakers of 5 outboard amps(5 each and separate power supplies, transformers, memory, not to mention total power)in a 5 channel set up.
Dedicated circuit - A DAC is a good example here. A separate dac (MSB or Monarchy which are not expensive at all) performs better than any DACs on three receivers (Yamaha RXV-1, HK AVR 8000, and Onkyo TXDS777)that I had the unfortunate experienced of owning/auditioning. I kept the RXV-1 as a processor and bought a separate dac and amps for 2ch-5ch listening on my HT system. Of course, the manufacturers of these receivers have the capability to improve the DACs but the biggest limitation is the real state it will take for the circuit design inside the receiver. Remember, inside the receivers not counting the DAC, you still have to accomodate processor circuits, display and control circuits, several channels of pre-amplification and power amplication, power supplies, wirings etc. In short, outboard DACs are way better because that's all they do and there is no compromise. All the design and improvements are aimed at one purpose only, that is to improve its Digital to Analog conversion capability
Upgradeability - This is self explanatory. For separates, you can hand pick (or ear pick) the preamp/processor, amp, dacs, and cabling to your liking (or to your wife's liking). On a receiver, what you see is what you get (WYSIWYG)! Although, you can always improve amplification by buying a separate amp and using your receiver's pre-out capability. But would that mean you are "quasi-separates" already?
Of course, the descriptions above were my experienced when I was in the "receiver" state of mind. I will never go back to it IMHO since moving to separates is nothing short of a revelation to me.
...to inform, not to convince....